Glossary of Terms used in the AV Industry which may help you demystify the concepts and technology a bit. If we are missing anything or you have a specific question, please contact us.
HDMI - A multipurpose Digital connection that carries the picture, sound, network connection, two-way control and anti-copy protection all in one convenient cable. From the user's point of view, the two main drawbacks are,
1. Can be mechanically weak if large bulky, heavy wires are used.
2. Length of cable could restrict the maximum resolution.
Interconnects - A generalised term given to analogue & digital cables connecting from one device to another which allows for audio signals to pass from one device to another.
Phono Connections - A generalised term given to the connector at the end of an analogue or digital coaxial cable and can also be described as an RCA. The connector consists of Central pin which is the positive (or Hot) and the outside ring is the negative(or Cold) and includes the grounding(earthing) for the signal.
XLR Connections - This is more commonly used as a professional connection. It is designed to to be reliable and noise-free. The XLR consists of three pins, the positive, negative and independent ground. These are all encased in a locking connector which prevents airborne noise and RF from attacking the signal inside.
Digital (SPDIF) Connections - Short for (Sony / Philips Digital InterFace) this is a digital signal that is transmitted via a phono lead. A single cable can carry up to 6 channels of information via bitstream, alternatively two channels of PCM digital signal.
Digital (TOSLINK) Connections - Short for (Toshiba link) another method of carrying a digital signal up to 6 channels via a fibre-optic lead. AVR Hardware Short for (Audio Visual Receiver) these are a single box that contains everything that you need, amplification, video & audio switching, audio processing and a tuner (all amplifiers with a built-in tuner, are considered to be receivers). All you need to do is add speakers and source, and you're ready to go.
Processor Hardware - A processor generally takes care of just two jobs. The most critical of which is decoding and processing of the soundtrack, whether that's a stereo or multichannel soundtrack the processor will handle every aspect of making sure that the right signal gets the right speaker at the right time. The second job is switching inputs, making it easy for you to select the source you want to listen to or watch.
Amplifier Hardware - An amplifier, is an electronic device that can increase the power of a signal before it goes to the speakers.
Projector Hardware - A projector enables you to mimic your local cinema and have a massive Picture in the comfort of your own home. For home theatre (or should that be theater??) / home cinema use, there are four flavours of projector available, DLP, LCD, LCoS & Laser. All of these come with their own pros and cons.
Screen Hardware - A projection screen is an installation consisting of a surface and a support structure used for displaying a projected image for the view of an audience. You generally have to choose whether you want a permanent installation of a fixed or retractable screen or a temporary/mobile screen.
Source Hardware - Is a device that is used for playback, for example, Apple TV, Amazon Stick, BluRay Player, Sky Box, Turntable, Mobile phone. Basically anything that contains content that you want to watch or listen to.
Audyssey Processing - The first Audyssey technology was released in home theatre receivers in 2004. It addressed the adverse effects of room acoustics on sound reproduction. Audyssey MultEQ: A technology that allows consumers and professionals to fix the acoustical problems in rooms that arise from the interaction of sound from the speakers with the surfaces in the room. MultEQ uses acoustical measurements in the time domain taken by a microphone around the listening area and combines this information to evaluate the acoustical problems that cause audible distortions in the frequency response. MultEQ then creates a room equalisation filter for each speaker and subwoofer in the system to correct these problems. Audyssey EQ is a direct extension of MultEQ for products that come with attached loudspeakers such as televisions and home theatre in a box system.
DIRAC Live Processing - Dirac Live® is a state-of-the-art digital room correction technology that employs a sophisticated analysis of your speakers and listening room to optimise the speakers’ overall audio performance and remove sound colourations introduced by the room. The result is substantially improved musical staging, clarity, voice intelligibility, as well as a deeper tighter bass.
Dolby Atmos Processing - Dolby Atmos is a surround sound technology developed by Dolby Laboratories. It expands on existing surround sound systems by adding height channels, allowing sounds to be interpreted as three-dimensional objects. This is a soundtrack that exists on the source, and you use a Dolby surround decoder to playback this signal.
Dolby Surround Processing - This is a decoder found inside the AVR or processor. It will decode all previous versions of Dolby's technology and map the correct signals to the right speaker.
DTS-X Processing - DTS:X allows the "location" (direction from the listener) of "objects" (audio tracks) to be specified as polar coordinates. The audio processor is then responsible for dynamically rendering sound output depending on the number and position of speakers available.
THX Processing - The THX system is not a recording technology or format, and it does not specify a sound recording format: all sound formats, whether digital (Dolby Digital, DTS) or analogue "shown in THX". This is a set of post-processing technologies that allow you to get closer to what the artist intended by taking care of the audio difficulties that you get when you take a movie soundtrack for the big screen which happens to be in a big room (Cinema) and play that soundtrack back in a small room(your lounge, media room).
5.1 Sound - Six discrete (unique) channels of information. Left, Centre, Right, Surround Left, Surround Right and the LFE. 5 Indicates the number of full range speakers, usually in odd numbers. 1 indicates the number of LFE / Subwoofers (Can be more than 1)
7.1 Sound - Eight discrete (unique) channels of information. Left, Centre, Right, Surround Left, Surround Right, Surround Back Left, Surround Back Right and the LFE. 7 Indicates the number of full range speakers, usually in odd numbers. 1 indicates the number of LFE / Subwoofers (Can be more than 1)
5.2.2 Sound - Nine discrete (unique) channels of information. Left, Centre, Right, Height Channel Left, Height Channel Right, Surround Left, Surround Right and the LFE. As with 5.1 and 7.1 etc these are the number of standard channels, the Subwoofers and the additional height channels. This is how Dolby Atmos & DTS:X channels are indicated. Usually grouped in equal pairs.
Centre Channel - This is the most important speaker in the system. Over 85% of the information that you're going to hear, comes from this channel.
Cross-Over - Crossover is a circuit whether it is digital, analogue or even software where frequencies are prevented from moving further down the chain. An analogue crossover would be inside the speaker, it will have a highpass and lowpass filter stage creating the crossover, this will allow all of the high frequencies to pass to the tweeter and stop the low frequencies. Then the lowpass filter allows all the lower frequencies to pass to the mid/ bass driver and stops any high frequencies getting to it.
Effects Channels - These are anything other than the left centre right and subwoofer channel. The Effects channels help create a sense of space within the home theatre/Home cinema and help give directional information to and away from the screen.
LCR Channels - These are the main front speakers, that draw your focus onto what is happening on the screen. They are usually identified as front Left - Centre & Right.